1. Technical Field
The present invention is directed toward window operators, and more particularly toward window operators which may be selectively motor driven or manually driven.
2. Background Art
There are, of course, any number of different types of window (and other closure) operators which are well known in the art. Examples of such operators are shown, for example, in Van Klompenburg U.S. Pat. No. 4,136,578, Van Klompenburg et al. U.S. Pat. No. 4,241,541, Peterson et al. U.S. Pat. No. 4,253,276, Erdman et al. U.S. Pat. No. 4,266,371, Nelson U.S. Pat. No. 4,305,228, Sandberg U.S. Pat. No. 4,346,372, Vetter U.S. Pat. No. 4,497,135, Tacheny et al. U.S. Pat. No. 4,521,993, Vetter U.S. Pat. No. 4,617,758, Allen U.S. Pat. No. 4,823,508, Tucker U.S. Pat. No. 4,840,075, Nolte et al. U.S. Pat. No. 4,843,703, Nolte et al. U.S. Pat. No. 4,845,830, Tucker U.S. Pat. No. 4,894,902, Tucker et al. U.S. Pat. No. 4,937,976, Nolte et al. U.S. Pat. No. 4,938,086, Berner et al. U.S. Pat. No. 4,945,678, Tucker et al. U.S. Pat. No. 5,054,239, Tucker et al. U.S. Pat. No. 5,152,103, and Vetter et al. U.S. Pat. No. 5,199,216.
Generally speaking, such operators have used a variety of linkages in combination with suitable hinge structures, where the operator linkages are actuated by rotation of a manual or powered drive connected to the linkage through assorted worm gear drives.
Design of acceptable operators is difficult due to numerous, sometimes contradictory, requirements. For example, it is necessary to provide operators which are able to withstand the extremely high loads often encountered by operators (when, for example, breaking the weatherstrip seal during initial opening of the sash and when closing the window sash to seal about the entire periphery of the weather strip).
Notwithstanding these strength requirements, it has been aesthetically necessary to minimize the size of operators in order to minimize the intrusion of the operator into the open viewing area provided through the pane opening of the sash.
The strength requirements have also heretofore necessitated the use of high strength, and relatively costly, materials (such as suitably hardened metals) in the drive train of the operator. Such materials are inherently susceptible to corrosive environments such as are commonly found in many areas, particularly in seaside dwellings. In order to provide a long useful life for the operator, various attempts have been made to coat or treat the metal components to resist corrosion. However, even the most successful of such treatments can significantly increase the cost of manufacturing the operator.
Yet another requirement in many window operator installations is the ability to drive the operator by an electric motor. However, since such motors are required to overcome the previously discussed high loads typically encountered by such operators, relatively expensive high power motors have typically been required. Of course, use of these motors in high load conditions also makes them susceptible to early burn out, in which case they provide neither the low cost nor the long useful life required in such units.
Prior art operators have to varying degrees been unable to address all of the above design constraints in a suitable manner.
The present invention is directed toward overcoming one or more of the problems set forth above.